The objective of the proposed research is to identify in Hepatoma Tissue Culture cells, those plasma membrane proteins, particularly glycoproteins, whose level can be altered by hormone particularly steroid hormones and the polypeptide hormones, glucogen and insulin. Towards this end, membrane glycoproteins would be identified by two-dimensional-polyacrylamide gel analysis of cells labeled metabolically with either fucose, mannose, or amino acid precursors. The surface localization of these proteins would be verified by cell fractionation techniques and by external labeling using lactoperoxidase catalyzed iodination to label tyrosine residues of membrane proteins and NaB3H4 reduction of galactose oxidase-treated cells to label external galactose and galactoseamine residues of glycoproteins and glycolipids. Using these types of techniques, we have shown that glucocorticoids alter both cell adhesiveness and the composition of surface glycoprotens of Hepatoma cells growing either in culture or as solid tumors in the animal. We propose to purify such hormone "inducible" glycoproteins from the solid tumor. Antibodies then would be prepared either in rabbits or using the "hybridoma" approach. Specific antibodies in combination with radioisotopic and cell fractionation methods would be used to trace the intracellular pathway of biogenesis of the inducible membrane proteins. Variant hepatoma cells have been and will be selected for differences in adhesiveness or other cell membrane-mediated alteratons in response to hormone treatment. The surface membrane polypeptide composition and metabolism in these cells will be examined in the hope of defining causal relationships between the presence and absence of specific plasma membrane proteins and cell behavior such as adhesiveness or cell-cell aggregation.